Police, firefighters and emergency personnel responded around 8 p.m. after a westbound Buel XB12 motorcycle, driven by Alden Shelley, 23, of Owl's Head Maine, and a Chevy Blazer driven by Thomas Roux, 54, of Farmington, collided near Cocheco Veterinary Hospital, according to Sgt. Michael McNeil.

McNeil said Shelley, who was not wearing a helmet, was airlifted from the scene to Maine Medical Center in Portland. He said Shelley was in critical condition as of Saturday night.

While her identity has not been released, McNeil said New Durham ambulance crews transported a female passenger to Frisbie Memorial Hospital in Rochester for non-life threatening injuries. He added she was transported to the hospital as a precaution.

McNeil said Roux and his passenger escaped injuries.

"Everything is under investigation at this point," McNeil said, adding road conditions were normal, but investigators have not ruled out whether speed, alcohol or mechanical issues were involved.

McNeil said Roux agreed to have his blood tested and investigators are checking to see whether the motorcycle's lights were working.

Route 11 was closed for several hours as firefighters, police and members of Strafford County Technical Accident Reconstruction team worked at the scene. McNeil said police from Middleton, Milton and New Durham responded to help local officers.